Hydrocarbons, such as oil and gas, are commonly obtained from subterranean formations that may be located onshore or offshore. The development of subterranean operations and the processes involved in removing hydrocarbons from a subterranean formation typically involve a number of different steps such as, for example, drilling a wellbore at a desired well site, treating the wellbore to optimize production of hydrocarbons, and performing the necessary steps to produce and process the hydrocarbons from the subterranean formation.
Upon drilling a wellbore that intersects a subterranean hydrocarbon-bearing formation, a variety of downhole tools may be positioned in the wellbore during exploration, completion, production, and/or remedial activities. For example, sensor components may be lowered into the wellbore during drilling, completion, and production phases of the wellbore. Such sensor components are often lowered downhole by a wireline, a slickline, a work string, or a drill string, and the sensors are used to perform a variety of downhole logging services. Sometimes the sensors are coupled to communication systems for conveying data indicative of sensed downhole parameters from the downhole sensor component to a surface location. For example, the downhole system (e.g., wireline, slickline) may utilize a fiber optic communication system for relaying sensed parameter measurement data from the downhole sensor to the surface for evaluation in real time or near real time.
In existing optical communication systems, an optical fiber is typically used to guide and propagate light waves from a source to a receiver (or detector). Light wave sources are often unable to operate at high temperatures experienced in a wellbore, so the sources are often positioned at a surface of the wellbore instead of downhole. Unfortunately, existing methods for communicating sensor signals from downhole to the surface using optical fibers (with a surface-positioned source and receiver) are generally limited to low sensitivity levels. For example, communication systems that use external optical or electrical modulation components positioned downhole along the optical fiber can lead to undesirable variation in the sensor data signal, due to losses at the interface between the fiber and the modulation components. In addition, these modulation components tend to add undesirable bulk to the optical fiber communication system. Some fiber communication systems are designed to sense downhole properties based on mechanical changes to the fiber itself, but these systems are limited to sensing a small range of properties at relatively low sensitivities.